Reclosable fastener assemblies are useful for sealing thermoplastic bags. Such fastener assemblies often include a plastic zipper and a slider. Typically, the plastic zippers include a pair of interlockable fastener elements, or profiles, that form a closure. As the slider moves across the profiles, the profiles are opened or closed.
The profiles in plastic zippers can take on various configurations. For example, U.S. Pat. No. 5,140,727 describes interlocking rib and groove elements, whereas U.S. Pat. No. 5,007,143 describes a rolling action zipper profile, and U.S. Pat. No. 4,747,702 describes profiles that are U-shaped with interlocking hooks.
The sliders for opening or closing the reclosable fasteners are generally shaped so that the slider straddles the profiles. The sliders often include a separating element that is inserted through the profiles in order to open the fastener. Such a slider is described in U.S. Pat. No. 5,067,208. In other types of sliders, the separating element does not penetrate the profiles, but rather, slides above the profiles on a specially adapted track located above the profiles, as described in U.S. Pat. No. 5,007,143. The separating elements have various shapes. For example, U.S. Pat. No. 3,173,184 describes a V-shaped separating element, while U.S. Pat. No. 5,067,208 describes a tapered separating element with a circular end.
A disadvantage of the known fastener assemblies is that thermoplastic bags incorporating the fastener assemblies often leak. Another disadvantage of the known fastener assemblies is that the zippers can be rigid and not very flexible, while the sliders can be large, cumbersome and expensive to manufacture. It would be an advance in the art of reclosable fastener assemblies to have a simplified slider, while minimizing leakage of liquids through the closure.